Caffeine Safe Limits: Determine Your Safe Daily Dose


Caffeine Safe Dose Calculator

Your Weight

A safe caffeine limit is the amount of caffeine a person can consume without experiencing any negative caffeine overdose symptoms.

It’s difficult to assign an exact amount for everyone because people can have different sensitivities or reactions to caffeine based on age, medical history, and tolerance.

However, there is enough research available to make a recommendation based on an individual’s weight.

Caffeine Amounts for Healthy Adults

For healthy adults with no medical issues, it is generally agreed upon that 300mg-400mg of caffeine can be consumed daily without any adverse effects.¹ The research behind this number actually bases this on a person’s bodyweight. So if you weigh more than the average human, you can safely consume a little more but if you weigh less than the average human you should consume a little less. Our safe dose calculator above reflects this.

This is equivalent to about:


A large review by European Food Safety Authority concluded that a daily safe dose of 400mg is safe for adults and single doses of 200mg at one time are fine for those engaging in exercise directly after the dose.

Based on on average body weights worldwide7, we conclude that 6mg/kg (of weight) is appropriate. Calculate your daily maximum for any drink here.

Safe Limits for Children

Because children’s brains are continuing to develop and their bodies are still growing, limited caffeine is recommended.

A recent study from The University Children’s Hospital in Zurich showed the importance of sleep for a child’s developing brain. Caffeine can interfere with sleep, therefore, possibly hindering proper brain development.

Ages 12 and Under

Caffeine isn’t recommended for children under 12. Occasionally, some doctors may recommend caffeine for children diagnosed with ADHD, but generally, there really is no reason for children under 12 to consume caffeine.

For children 4 or older an occasional caffeinated soda or chocolate treat will likely pose no concern and around 45mg per day¹ is recognized as a safe amount, but caffeine shouldn’t be a daily part of a child’s diet.

Ages 13-18

While greatly limiting caffeine to this age group would be ideal, because of the increasing demands placed on teenagers in regards to school, sports, and even work; caffeine consumption is becoming more common with this age group.

Developing teens should have no more than 100mg of caffeine daily² due to the importance of sleep, brain development, inexperience with caffeine, and possibly unknown medical conditions.

This is equivalent to about:

  • 1.3 Shots of espresso
  • 1.25 8 fl.oz. Red Bulls
  • .5 of a 5 Hour Energy Shot
  • .6 of a 16 fl.oz. can of Monster Energy Drink
  • .2 of a Starbucks Venti brewed coffee
  • 3 12 fl.oz. Cokes

The European Food Safety Authority also stated in their draft report that for children ages 3-18; 3mg of caffeine per kilogram of body weight seems safe. i.e. a 20kg child could safely consume 60mg of caffeine6.

Caffeine for Those with Health Concerns

Adults, as well as children, with either diagnosed or undiagnosed medical conditions, can have adverse health implications with even small amounts of caffeine. For those with certain health conditions, giving up caffeine may be recommended. Here are some conditions that usually warrant quitting caffeine or caution consuming the drug. We recommend using Wean Caffeine to gradually quit caffeine instead of quitting all at once which is a huge shock to your system.

Heart Conditions

Because caffeine is a stimulant, it increases heart rate as well as blood pressure. Therefore, those with heart arrhythmias³, murmurs, and hypertension should limit their caffeine intake.

It’s important to note that caffeine hasn’t been proven to cause arrhythmia, heart disease or other heart-related problems.¹

Those with pre-existing arrhythmias, murmurs, and hypertension should limit caffeine to no more than 200mg daily and are advised to consult their physician before consuming caffeine.

Type 2 Diabetes

The majority of the research shows that caffeine doesn’t increase the risk of someone developing type 2 diabetes, but actually decreases risk.¹

However, those already diagnosed with type 2 diabetes should limit caffeine consumption because it can impair glucose metabolism in diabetics.4

Those with type 2 diabetes should restrict their consumption to around 200mg daily or follow their doctor’s instructions concerning caffeine intake.

Pregnant or Nursing Women

We have covered pregnancy and caffeine extensively in our article located here.

In summary, we concluded that mothers consuming 200mg of caffeine or less a day results in very little risk for the developing fetus and nursing infant.

200mg of caffeine is equivalent to about:

  • 2.6 shots of espresso
  • 2.5 8 fl.oz. Red Bulls
  • One 5 Hour Energy Shot
  • .5 of a Starbucks Venti Brewed Coffee
  • 1.25 16 fl.oz. Monster energy drinks
  • 6 12 fl.oz. Cokes

Those Ultra-Sensitive to Caffeine

For those ultra-sensitive to caffeine it is hard to determine an exact caffeine safe limit. Some people can have one cup of coffee (100mg-120mg) in the morning and still fail to get to sleep that evening. This is well after the caffeine’s effects should have worn off as it does for “normal” caffeine consumers.

If the ultra-sensitive choose to consume caffeine they should do so in small amounts until they find the amount that works, but doesn’t cause unwanted side-effects.

We suggest that these people start with 50mg of caffeine daily and then slightly increase or decrease their consumption from there.

This is equivalent to about:

  • 1.5 12 fl.oz. Cokes
  • 1 4 fl.oz. brewed coffee. (not Starbucks)
  • 1 8 fl.oz. strong black tea
Need help with caffeine levels? Check out our huge list of caffeine amounts.

A General Guide to Caffeine Consumption Only

Our caffeine safe limit amounts listed above are based on what the latest research tells us and should be used as a general guide, not the “gospel’.

There are just too many variations in the human population to determine a safe limit for caffeine use in ALL people.

Caffeine should be treated as any other drug and used with caution until a person understands how it interacts with his/her particular genetic make-up and health profile.

It’s also important to understand that a person’s safe limit of caffeine can change over time as a person’s health evolves over his/her lifetime.

How Much Caffeine Are Americans Consuming?

The Department of Nutritional Sciences from The Pennsylvania State University recently conducted a survey study and found that on average, those ages 50-64 consume the most caffeine daily.

The most shocking part of their data is the fact that 2 to 5-year-olds consume on average 24mg of caffeine daily. This means that many would consume much more.

We populated their data into the graph below.


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  • Ted

    I think you are referring to Anais Fournier. she drank 2 Mega Monsters and she had an underlying heart condition.

  • 3ndlesswars

    If you honestly are studying the affects. I have drank an entire 12 pack of SLAP Energy drink within a period of around 5-7 hours. I felt really sick the next morning, though nothing beyond, a general headache and slight nausea, other than that I was fine, and the sick feeling wore off after about an hour or two of being awake.

  • The fact that you got sick indicates there was some sort of systemic reaction. Taurine can irritate the stomach if your stomach is empty because taurine works by helping foods get absorbed more quickly. Your body makes taurine but obviously it knows better than to release it on an empty stomach. It won’t hurt you it will just be there with nothing to do, kind of like a taxi cab in an empty airport, so the tummy gets irritated.

  • What I am currently interested in, and need to talk to other health professionals/biochemists about, is why some people show no reaction at all. Is it because the caffeine is not being absorbed?
    Or are those peoples’ liver enzymes so efficient it goes boom boom boom and can process caffeine instantaneously? I’m not sure yet so I’m looking into it.

  • Sid

    I’d be curious to know if there’s any sort of breakdown on the effects for people who have built up a massive caffeine tolerance. I typically drink between 4 and 8 large coffees daily. I can drink a huge 24 oz mug of strong coffee and go straight to bed. I can drink 6 espressos within 20 minutes and feel pleasant, but not remotely uncomfortable. lIt takes enormous amounts of caffeine for me to get the “jittery” feelings, or make my heart go into hummingbird mode.

    Many years ago, a small mountain dew was way, way too much caffeine for me. I don’t think I’m simply a freak of nature– I believe I’ve just gradually grown a tolerance. Does the tolerance grant you more leeway with adverse health side effects?

    Then of course there’s stuff like this: — coffee has health benefits in addition to some of the negatives that come with caffeine use. I’ve even seen a few articles that suggest that light caffeine use is good for you, moderate is bad, and heavy use is good again, as you body builds up resistance to the negative effects.

    But yeah, how about some love for us caffeine bingers?

  • Ted

    Hey Sid, Yes, we also have articles concerning the health benefits of coffee and some studies do show increased health benefits with 5+ cups and yes it is possible to build up tolerance over time.

    What we don’t know is how large doses of caffeine alter the brain or other organs over time. I would ask that you evaluate the reasons for needing to drink that much coffee and then decide if it’s worth the costs/benefits.

    check this resource out

  • Pierson Jones

    In one container of mio energy there are 1,080 mg of caffeine. Holy crud!

  • Well, let’s hope no one tries to drink the whole container or thinks the container is a drink all by itself.

  • lance

    66 grams of sugar is about 14 tsp not so safe, and caffeine 200 wow that’s a lot and cal at 130. I’ve found one with no sugar 8 cal and no caff with 18 flavors its filled with a lot if B vitaminsB12 is at 4900%

  • Well safety of sugar is hard to determine, as it’s one of those things that has long-term, chronic effects as opposed to immediate and obvious overdosing effects like certain drugs or certain vitamins. I try to limit added sugars and try not to drink my calories so glad you’ve found somethign with 8 calories. Something to watch out for is B12 – it’s one of those vitamins that doesn’t give you an energy boost if you have ten-fold the DV. All that hype about B12 injections is true only for people who are A)deficient in a particular enzyme that absorbs B12 or B)really susceptible to placebo effect. Here’s more info on the misuse of B12 for consumer appeal:

  • 7OLS

    HA HA growing up the most caffeine I’ve ever had was 350mg of caffeine and that was from that one energy drink, known as Spike Shotgun. I know some of you girls and guy’s out there, must’ve heard of it. I didn’t really have any heart problems or anything major like that. Thank God, I was alright. When I was 13, I used to drink a monster and take 10mg of Adderall XR, and hop on the school bus! HA HA when I was 13, I also used to drink 7 mountain dews and play video games all day. I grew up collecting energy drinks. Nowadays, I limit my caffeine intake. Nowadays, I’ll limit 250mg of caffeine at the absolute most. I’ve had plenty of side effects from caffeine though. I’ve had nervousness, shaking, paranoia, anxiety, trouble sleeping/insomnia, rapid heart beat, acne, jittery feeling, racing thoughts..etc I’ve never gotten diabetes or anything like that. When I was 12, I had my first energy drink and it was amp energy. I’ve been drinking mountain dew since I was 11 and I still drink mountain dew. Growing up from 13 to 17, I’ve definitely had a ton of caffeine. I have a collection of like 280+ energy drinks in my room right now! I’ve definitely had a lot of experiences with sleep deprivation and caffeine addiction. It never effected my growth though. I still grew. Right now, I’m 6 feet tall and 140lbs and I turn 18 on May 10th. I’m definitely a huge caffeine addict. I love mountain dew, bawls and Starbucks LOL!!!!!!!!!!!!

  • energyfanatic291

    hmm guess i should have followed these limits long ago when i was 11-12 i was drinking 1-3 monsters a day

  • Eric Schmid

    Okay so I am just curious, is 420mg in roughly 4 hours bad for an average 22 yr old male of 145 lbs on an empty stomach? and also does having an empty stomach matter?

  • Ted

    It really depends on your caffeine tolerance and sensitivity. For a healthy person 420mg in 4 hours is generally safe. Caffeine absorbs faster on an empty stomach, but can also cause an upset stomach if consumed this way. This amount would be similar to drinking a Starbucks Venti brewed coffee over a 4 hour period.

  • Rahat Hasan

    Well, uhm, I have my A Levels this month and I have to study all night and day. I’m getting about 6 hours of sleep everyday, at once. Is it okay, if I consume, like, 3 RedBulls in a time frame of, say, 6 hours?

    I’m just really concerned about consuming 180mg of caffeine in 6 hours :/

    Thankyou 🙂

  • Ted

    How old are you? If you are over 13, 180mg or 3 Red Bulls in 6 hours is acceptable. Compare it to having just 1 8 floz (short) Starbucks brewed coffee.

  • lauryn

    i am a fourteen year old girl and have had approximately 400mg of caffeine in less than an hour, is this dangerous?

  • Ted

    If could be especially if your body isn’t accustomed to caffeine. A girl your age should consume no more than 200mg per day.

    Tell your parents, drink plenty of water and if you start having severe overdose symptoms go to the ER.

  • K A

    I’m sticking with tea,especially green tea. And 3 espresso/week to maintain my blood pressure. it works so far:)

  • Ted

    good to hear. How much did your blood pressure lower from doing this?

Last Modified: November 16, 2017